Introduction: Synovium is the primary site of inflammation and is affected in variety of joint diseases. Examination of synovial tissue can assist in diagnosis of some joint diseases, and in several atypical and rare synovial disorders. This study aims to describe the histomorphological changes in synovium and to evaluate the clinical presentation and radiological findings in various joint diseases.Aim of the study:To describe the clinical presentations, radiological findings and histomorphological changes in various synovial lesions. Materials and Methods: This was a prospective, descriptive type of study done over a period of two years. All synovial biopsy specimens sent from department of Orthopaedics in the study period were subjected to routine histopathological processing. The clinical and radiological details were collected. The radiological and histopathology findings were compared and the morphological features in various synovial/joint diseases were studied. Results: A total of 120 synovial tissue specimens were studied. The age group in this study ranged from 3 years to 77 years. The male to female ratio was 1.4:1. The most common joint involved was knee joint (74 cases, 61.7%). Common clinical features were of pain and swelling of the affected joint. Majority of cases had no significant radiological abnormality (72.5%). Others showed nonspecific findings (10.8%), degenerative changes (10%), and loose bodies (6.7%). The most common morphological change was synovial hyperplasia. (92 cases, 76.7%). The most common inflammatory infiltrate was lymphocytes (45 cases, 37.5%). The most common lesion found in synovial biopsy was non-specific synovitis (33 cases). Conclusion: Synovial pathology is common in 41–50 years males and presents often with pain and swelling. The most commonly involved sites are large joints like knee and hip and majority of cases do not show significant radiological abnormality. The most common synovial lesion in our study was non-specific synovitis. Inflammatory lesions have various etiologies. Degenerative changes show varied morphology. Tumor and tumor-like conditions can also be encountered.

Keywords: Synovial biopsy; Joint disease morphology; Synovitis; Rheumatoid arthritis.